Metamath Proof Explorer


Theorem opthneg

Description: Two ordered pairs are not equal iff their first components or their second components are not equal. (Contributed by AV, 13-Dec-2018)

Ref Expression
Assertion opthneg AVBWABCDACBD

Proof

Step Hyp Ref Expression
1 df-ne ABCD¬AB=CD
2 opthg AVBWAB=CDA=CB=D
3 2 notbid AVBW¬AB=CD¬A=CB=D
4 ianor ¬A=CB=D¬A=C¬B=D
5 df-ne AC¬A=C
6 df-ne BD¬B=D
7 5 6 orbi12i ACBD¬A=C¬B=D
8 4 7 bitr4i ¬A=CB=DACBD
9 3 8 bitrdi AVBW¬AB=CDACBD
10 1 9 bitrid AVBWABCDACBD